Electrosurgical apparatus for cutting and the coagulation of tissue requires supplying a wide range of power outputs to the active electrode for a wide range of surgical procedures.
Klicek U.S. Pat. No. 4,658,820 discloses a waveform generator that stores several waveforms in an MxN storage device, each of these several waveforms being available simultaneously at the output of the storage device and with the desired waveform selected by a multiplexer. That disclosure requires that the read access time of the storage device be less than the highest bit rate of the resulting waveform, that each waveform length must be of a common multiple of every other waveform length, and that the number of waveforms that can be stored is limited by the length of the multiplexer used to select the output waveform. Those requirements place severe restrictions on the upper waveform frequency, diversity of waveform length, and the number of waveforms that may be used.